from typing import Optional
from typing import Dict, Any, Union
from datetime import datetime

from pydantic import BaseModel, Field, ConfigDict
from app.models.enums import TaskStatus, TaskType

class DecodeTaskParams(BaseModel):
    filename: str = Field(..., description="文件名")
    sheet_name: str = Field(..., description="工作表名称")
    decode_type: str = Field(..., description="解码类型")
    header: str = Field(..., description="解析列")
    model: Optional[str] = Field(None, description="模型名称")

class DecodeTaskResult(BaseModel):
    filename: str = Field(..., description="结果保存文件名")
    spend: float = Field(..., description="任务耗时")
    rows: int = Field(..., description="解析行数")

class TaskResponse(BaseModel):
    id: int
    name: str
    type: TaskType          # ← Pydantic 会自动转为字符串
    params: dict
    status: TaskStatus      # ← 同上
    result: Optional[dict]

    class Config:
        from_attributes=True
        use_enum_values = True  # ← 关键！将 Enum 转为值（如 'pending'）
        # 或者在 Pydantic v2 中：
        # model_config = ConfigDict(use_enum_values=True)

class TaskModel(BaseModel):
    name: str
    type: TaskType  # Enum: e.g., "decode", "upload", etc.
    params: Dict[str, Any]  # 存储原始参数字典
    status: TaskStatus
    result: Optional[Dict[str, Any]] = None

    @classmethod
    def create_decode_task(
        cls,
        name: str,
        params: DecodeTaskParams,
        status: TaskStatus = TaskStatus.PENDING
    ) -> "TaskModel":
        """创建解码任务的工厂方法"""
        return cls(
            name=name,
            type=TaskType.DECODE_ORDER,
            params=params.dict(),
            status=status
        )

    def get_params(self) -> BaseModel:
        """反序列化 params 为具体模型"""
        if self.type == TaskType.DECODE_ORDER:
            return DecodeTaskParams(**self.params)
        raise ValueError(f"Unknown task type: {self.type}")

    def set_result(self, result: Union[DecodeTaskResult]) -> None:
        """设置结果（自动序列化）"""
        if self.type == TaskType.DECODE_ORDER:
            self.result = result.dict()
        else:
            raise ValueError(f"Unsupported result for task type: {self.type}")

    def get_result(self) -> Optional[BaseModel]:
        """反序列化 result 为具体模型"""
        if self.result is None:
            return None
        if self.type == TaskType.DECODE_ORDER:
            return DecodeTaskResult(**self.result)
        raise ValueError(f"Unknown task type: {self.type}")